The Kingdom of Prussia at its greatest extent (in blue), at the time of the formation of the German Empire, 1871 (in tan). Source: [http://commons.wikimedia.org/wiki/Main_Page Wikipedia Commons]The Free State of Prussia (blue), within Germany (tan

The Kingdom of Prussia at its greatest extent (in blue), at the time of the formation of the German Empire, 1871 (in tan). Source: [http://commons.wikimedia.org/wiki/Main_Page Wikipedia Commons] Wikipedia Commons The Free State of Prussia (blue),